Wire forming machines



April 18, 1967 F. c. HOLMES 3,314,453

WIRE FORMING MACHINES Filed June 10, 1964 4 Sheets-Sheet l I NVENTOR.

A ril 18, 1967 Filed June 10, 1964 F. C. HOLMES WIRE FORMING MACHINES 4Sheets-Sheet 2 INV NTOR. BY zwmiw April 18, 1967 F. c. HOLMES WIREFORMING MACHINES 4 Sheets-Sheet 5 Filed June 10, 1964 INVENTOR. BY MK$4M arr/mums.

Patented Apr. 18, 1967 3,314,453 WIRE FORMING MACHINES Frank C. Holmes,Trumbull, Conn., assignor to The U.S. Baird Corporation, Stratford,Conn., a corporation of Connecticut Filed June 10, 1964, Ser. No.374,040 6 Claims. (Cl. 140103) This invention relates to Wire formingmachines and, more particularly, to a spring forming machine forproducing coil springs having open spaced body coils.

In United States Patent 3,025,889, which issued Mar. 20, 1962, to MurrayG. Clay, there is disclosed a wire forming machine, including aplurality of individual defleeting tools which are movable into and outof an operative position in front of an orifice provided in a guidethrough which the wire is fed. These tools cause deflection and coilingof the wire in different directions and in different planes. The threetools are programmed in such a manner that, as the wire issues from theorifice, a first tool forms a loop. As the first tool is withdrawn, asecond tool moves into position so that the portion of the wireprojecting from the orifice is deflected down wardly. Further wire thatissues from the orifice is then curled against the side of a guide toform the body portion of a coil spring. After the prescribed number ofcoils have been formed, the second tool is retracted and a third toolmoved into position to form another loop. The completed spring is thencut off and the operation is performed again on the succeeding length ofwire.

Although the machine disclosed in the above mentioned patent is highlysuccessful for the manufacturing of coil springs, all the springs whichit produces are of the type wherein the coils lie tightly against oneanother. Many applications, however, require springs having open spacedcoils and it would be desirable to form such coils with a machine of thegeneral type disclosed in the above patent. Furthermore, it would bedesirable to produce such springs without the use of additional wiredeflecting tools.

Accordingly, it is a primary object of this invention to provide animproved wire forming machine. Other objects are to provide such amachine which is capable of producing coiled wire springs having openspaced coils; which is capable of producing open spaced coil springshaving end loops; which is capable of producing such springs whileutilizing the same number of defiective tools as the patented machine;and which is capable of producing springs having variable coil spacing.

The manner in which the foregoing objects are achieved will be moreapparent from the following description, the appended claims, and thefigures of the attached drawings, wherein:

FIG. 1 is a front view of a wire forming machine embodying the presentinvention;

FIG. 2 is a right elevational view of the machine of FIG. 1;

FIG. 3 is a cross section taken along the line 33 of FIG. 2;

FIG. 4 is a perspective view of the wire guide and associated tools inwhich a tool has moved into position .for forming the first loop of acoil spring;

FIG. 5 is a view similar to FIG. 4 showing the coil body forming toolmoving into position as the first loop forming tool is retracted;

FIG. 6 is an enlarged plan view of the wire guide showing the secondloop forming tool moved into position to function as a coil spacer;

FIG. 7 is a perspective view showing the relationship of the machineparts during the production of the spring body;

FIG. 8 is a view similar to FIG. 6 showing the body forming toolretracted and the second loop forming tool beginning to move around theend of the wire guide to form the second loop;

FIG. 9 is a view similar to FIG. 8 shOWing the second loop forming toolforming the end of the second loop;

FIG. 10 is an illustration similar to FIG. 9 showing the completedspring being severed by the cutoff tool;

FIG. 11 is a cross section taken along the line 11-11 of FIG. 3; and

FIG. 12 illustrates the operation of the machine employing a second loopforming tool having a broader wedge angle.

The machine of this invention has certain basic similarities to themachine disclosed in the above-mentioned patent. In the drawings, themachine 10 is adapted to form a length of wire W into a predeterminedspring configuration. The machine comprises a head 20 secured to a faceplate 21. The head 20 includes a forwardly protruding wire guide 22having a longitudinal guide channel 24 extending therethrough. Rockerarms 26, 28, and 30 are mounted on the head to carry forming tools intoand out of a forming position in front of the wire guide.

The wire feeding mechanism comprises a pair of feed rolls 32 and 34disposed behind the wire guide so as to feed a predetermined length ofwire W through the guide during each machine cycle.

The rocker arm assemblies 26, 28, and 30 are mounted on spindles 36, 38,and 40 which extend outwardly from the head in a plane perpendicular tothe wire feed axis, the adjacent spindles being perpendicular to eachother. Each rocker arm is adapted to oscillate on its spindle inresponse to action of the operating mechanism at the rear of the head.As is illustrated in FIGS. 1 and 4,'the rocker arm 26 mounted ondownwardly extending spindle 36 is provided on one end with a toolholder assembly 42 which carries a forming tool 44 which extendsradially inward towards the wire guide. The function of tool 44 is toproduce the first loop 16 on the end of the advancing wire asillustrated in FIG. 4.

The rocker arm 28, mounted on horizontally extending spindle 38, isprovided on one end with a tool holder assembly 48 which extendslaterally above the wire guide and carries forming tool 50. The functionof tool St) is also the same as that of the correspondingly numberedtool shown in the patent, namely, to deflect the wire downwardlyproducing the coils of the spring body. The illustration of FIG. 5 showscoil forming tool 50 positioned for forming the coils.

The present invention is primarily concerned with the movements ofrocker arm 39 and the tool which it controls. The rocker arm 30 ismounted on the upwardly extending spindle 40 and is provided at one endwith a tool holder assembly 54 which extends downwardly and carries atool support block 56 at its lower end. Support block 56 is sopositioned that its plane of movement during oscillation of the rockerarm 30 is below the axis of the wire guide 22.

A pivot block 58 is mounted on tool support block 56 so as to bepivotable about a pin 69 disposed through the forward ends of thesupport block 56 and the pivot block 53. Rotation of the block in acounter-clockwise direction (looking downward) is limited by anadjustable stop 61.

The block 58 carries an upstanding wire forming tool 62 which isdisposed rearwardly on the block from the pivot pin 60. Tool 62 isgenerally wedge shaped with the apex 64 of the wedge extending forwardlyand a horizont-al wire forming groove 65 (FIG. 6) disposed in the sideadjacent the guide. A spring 66 is attached to the support block 56 andbears against the rear portion of the pivot block 58 so that the pivotblock is normally urged in a clockwise direction as seen from the top.This results in the tool 62 resiliently bearing against the side of thewire guide 22 during a portion of the machines cycle.

To enable the machine to form a spring having a loop on each end, theforward end portion 68 of the side of the wire guide is substantiallyfiat, vertical, and parallel to the wire guide channel 24 and theopposite side of the guide is provided with a recess 70 (FIG. 6).

As described in the referenced patent, the operation of the rocker arms26, 28, and 30 to carry the wire forming tools into and out of theoperative position is controlled by pull rods 72, 74, and 76,respectively, and springs 78, 80, and 82, respectively. The pull rodsare operated by cam followers 84, 86, and 88 riding, respectively, oncams 90, 92, and 94. The operation of cams 9t} and 92, and the pullrods, springs, and rocker arms with which they are associated, is fullydisclosed in the referenced patent. Basically, the springs bias the rodsrearwardly tending to pivot the rocker arms so as to move the tools intotheir operative positions. The action of the cam followers is to permiteach spring to move its associated tool into position when the camfollower reaches a depression on the cam surface. The cams retract thetool as the cam followers rise out of such depressions.

A wire cutoff tool 96, (FIGS. 2 and 10) normally disposed below theguide 22, is mounted on a support bar 98 carried by brackets 100 and 102secured to the face plate 21. Cutoff tool 96 is adapted to be swungupwardly by any suitable mechanism at the completion of a wire formingoperation to shear off the wire at the end of the guide channel 24. Forcontrolling the motion of the completed spring after it has been cut offby the tool 96, a deflector 104 is mounted on tool 96 by a resilient arm106 which prevents upward movement of the spring after it is cut off.

The operation of a machine similar to that disclosed herein, but withoutthe novel spacing mechanism of this invention, is disclosed in thereferenced patent. As therein described, as the feeding of wire Wcommences, the rocker arm 26 pivots about its spindle to permit tool 44to move into position in front of the wire guide as shown in FIG. 4. Asthe wire feed continues, the wire is dedefiected laterally by tool 44 toform loop 16. When loop 16 has been completed, tool 44 is retracted.Just prior to the completion of loop 16, rocker arm 28 has commenced topivot to start tool 50 moving downwardly. As soon as tool 44 hasretracted, tool 50 almost immediately moves into position in front ofthe wire guide as shown in FIG. 5. The portion of the wire projectingfrom the guide is thereupon deflected downwardly and further wireissuing fromt he guide is deflected downwardly and coiled against theside 68 of the guide to form the body portion 14 of the spring. In theprior art machine, the tool 62 remains retracted during the formation ofthe spring body 14 so that the individual coils of the spring liealongside one another without spacing and tool 62 is not utilized untilafter the prescribed number of coils have been formed. Thereupon, therocker arm 30 pivots about its spindle so as to move the tool supportblock 56 through an are which passes across and under the axis of thewire guide while tool 50 is being retracted. This movement of thesupport block causes the tool 62 on the pivot block to slide for wardlyalong the side 68 of the guide so that the apex 64 of the tool passesbetween the side 63 of the guide and the most recently produced coilwhich is disposed thereagainst. This causes the body 14 of the spring tomove outwardly and tool 62 is then cammed around the end of the guide asshown in FIG. 9 so as to stop in a position in front of the guidechannel to form the rear end loop of the completed spring. Tool 62 isthereupon retracted and cut-off tool 96 swings upwardly shearing thewire :at the end of the guide.

It will be apparent that, in the patented machine, the tool 62 isutilized only for forming the rear loop of a coil spring. In the presentinvention, however, tool 62 is used for another purpose as wellnamely,for spacing the individual coils of the spring body 14 from one anotherby a predetermined amount. The manner is which this is accomplished isillustrated in FIG. 6. From this figure, it will be noted that, unlikethe patented machine, tool 62 has been moved into position between side68 of guide 22 and the newly forming coil of spring body 14. Tool 62operates in combination with the coil forming tool 50 to space the coilsof the spring body by an amount determined by the wedge shape of tool 62and by the extent of its advancement into the spring body 14. Uponcompletion of the spring body, tool 62 is caused to move forwardly alongside 68 and around the end of the guide 22 as illustrated in FIGS. 8 and9, so as to form the rear loop in the manner disclosed by the patent.

The cam 94 which actuates the tool 62 in such a manner as to form aspring body having spaced coils is most clearly illustrated in FIGS. 3and 11. Cam 94 is made up of three parts, a fixed portion 94:: and twowedge shaped adjustable sectors 94b, 94c. By adjusting the position ofsectors 94b, 94c, the dwell time of cam follower 88 at its maximumdisplacement from the center of cam 94 may be varied as required. Cam 94operates against cam follower 88 which is secured to an arm 110rotatably mounted on a pivot 112 and having a depending edge 110. Edge110 abuts against the back of an adjustable shoulder 114 secured to arod actuating arm 114. Arm 114 is pivoted to a fixed pivot 116 at oneend and to the rod '76 at the other. Cam 94 operates in a clockwisedirection as viewed from above. During formation of the initial loop 16,cam rider S8 is displaced to its maximum amount by means of the camsections 94b, 940. This displaces pull rod 76 outwardly and therebyretracts tool 62 away from the end of guide 22. As coil forming tool 50be gins to move into position, cam follower 88 rolls off of cam section94b onto cam section 94a. The correspond ing inward displacement of camfollower 88 allows pull rod 76 to be pulled inward under the influenceof spring 82 so that rocker arm 30 pivots about spindle 40 and advancestool 62 into the position shown in FIG. 6. The tool then remains in thisposition while the remainder of the coils forming spring body 14 areformed. Follower 88 then follows into the recess of cam 94, forcing tool62 around the end of guide 22 to form the final loo in the mannerpreviously described.

An additional advantage of this invention is that, by proper programmingof the various cams, springs may be formed having spaced coils and noend loops. Accord= ingly, by controlling tool 62 in the manner hereinde= scribed, there may be formed either tension springs hav= ing spacedcoils and a loop at each end or compression springs formed withoutloops.

A further modification of this invention is illustrated in FIG. 12. Thisfigure illustrates the manner in which the spacing of the coils of aspring body 14 may be varied In the illustrated modification, forexample, the tool 62' is designed with a larger wedge angle so that thecoils are displaced a greater distance from one another.

Many other variations and modifications may be made in this inventionwithout departing from its spirit and scope. Accordingly, the foregoingdescription is to be construed as illustrative only rather thanlimiting. This invention is limited only by the scope of the followingclaims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A wire forming machine which comprises: a fixed wire guide having arear end and a forward end and a bore therethrough terminating at saidforward end in a feed orifice; feed means for advancing wire throughsaid bore from said rear to said forward end; a coil forming toolmounted to be selectively advanced to a coil forming position adjacentthe forward end of said guide; a coil spacing tool mounted to beadvanced into a coil spacing position intermediate said wire guide andthe coils being formed by said coil forming tool; and means forselectively advancing said coil spacing tool into said coil spacingposition.

2. In a wire forming machine including a fixed wire guide having a rearend and a forward end and a bore therethrough terminating at saidforward end in a feed orifice, feed means for advancing wire throughsaid bore from said rear to said forward end, a first loop forming toolmounted to be selectively advanced to a loop forming psition adjacentthe forward end of said guide, a coil forming tool mounted to beselectively advanced to a coil forming position adjacent the forward endof said guide, and a second loop forming tool mounted to be selectivelyadvanced to a loop forming position adjacent the forward end of saidguide, the improvement which comprises: actuating means for partiallyadvancing said second loop forming tool to an intermediate coil spacingposition to space from one another the coils being formed by said coilforming tool.

3. The improvement of claim 2 wherein said actuating means com-prises:rotatable cam means having at least first, second, and third camsurfaces, each cam surface being displaced from the center of rotationof said cam means by a different amount; cam follower means arranged tosequentially contact said first, second, and third cam surfaces duringrotation of said cam means; first linkage means supporting said camfollower means and arranged to pivot in response to movement thereof;pivotally mounted rocker arm means having a first end and a second end;second linkage means connected intermediate said first linkage means andthe first end of said rocker arm means to pivot said rocker arm means inresponse to movement said cam follower means; and means sup porting saidsecond loop forming tool at the second end of said rocker arm means.

4. The improvement of claim 3 wherein said cam means is adjustable tovary the length of at least one of said cam surfaces.

5. A wire forming machine which comprises: a fixed wire guide having arear end and a forward end and a bore theret-hrough terminating at saidforward end in a feed orifice, said wire guide including a planarsurface along its forward end; feed means for advancing wire throughsaid bore from said rear to said forward end; a coil forming toolmounted to be selectively advanced to a coil forming position adjacentthe forward end of said guide; and a wedge shaped coil spacing toolmounted to be advanced into a coil spacing position intermediate saidwire guide and the coils being formed by said coil forming tool, oneplanar surface of said wedge shape being arranged to lie along saidplanar surface in said coil spacing position.

6. A wire forming machine which comprises: a fixed wire guide having arear end and a forward end and a bore therethrough terminating at saidforward end in a feed orifice; feed means for advancing wire throughsaid bore from said rear to said forward end; a coil forming toolmounted to be selectively advanced to a coil forming position adjacentthe forward end of said guide; and a coil spacing tool mounted to beadvanced into a coil spacing position intermediate said wire guide andthe coils being formed by said coil forming tool, said coil spacing toolbeing selectively moveable from said coil spacing position to a loopforming position adjacent the forward end of said guide.

References Cited by the Examiner UNITED STATES PATENTS 1,880,606 l0/l932Vanderploeg 140103 3,025,889 3/1962 Clay 140-71 3,025,890 3/1962 Clay14071 3,025,891 3/1962 Clay l-7l 3,240,238 3/1966 Sjobohm l03 X WILLIAMJ. STEPHENSON, Primary Examiner.

1. A WIRE FORMING MACHINE WHICH COMPRISES: A FIXED WIRE GUIDE HAVING AREAR END AND A FORWARD END AND A BORE THERETHROUGH TERMINATING AT SAIDFORWARD END IN A FEED ORIFICE; FEED MEANS FOR ADVANCING WIRE THROUGHSAID BORE FROM SAID REAR TO SAID FORWARD END; A COIL FORMING TOOLMOUNTED TO BE SELECTIVELY ADVANCED TO A COIL FORMING POSITION ADJACENTTHE FORWARD END OF SAID GUIDE; A COIL SPACING TOOL MOUNTED TO BEADVANCED INTO A COIL SPACING POSITION INTERMEDIATE SAID WIRE GUIDE ANDTHE COILS BEING FORMED BY SAID COIL FORMING TOOL; AND MEANS FORSELECTIVELY ADVANCING SAID COIL SPACING TOOL INTO SAID COIL SPACINGPOSITION.